Reactive Trace Chemicals in Ocean Surface Waters: Hydrogen Peroxide, Manganese and Gallium

活性痕量物质如Fe对海洋表面化学和生物生产力有重要影响。 然而，其他可影响初级生产、影响其他元素的化学分布或可用作示踪剂的痕量物质却较少受到关注。 为此，来自南密西西比大学的两名研究人员将参加第四次国际奥委会巡航西北太平洋，以确定地表水、垂直剖面、雨水样本、粉尘溶解实验和/或培养实验中的锰、过氧化氢和镓。沃茨。 H2 O2的测定将用于以下目的：（1）增加测量数据，以检查表面沃茨中灰尘的光化学溶解;（2）确定它是否有助于溶解海洋表面的微粒铁;（3）评估光产生和暗衰减的速率。 Mn值将与Al和Ga进行比较，以区分粉尘和货架投入。 此外，鉴于Mn在海洋表层的停留时间较长，PI将尝试使用这种金属来提供对上层海洋Fe输入的新见解。 Mn与H2 O2的比较将允许PI确定锰氧化物在海水中的还原溶解。 最后，Ga浓度将与Al进行比较，以评估前者是否可能不是海洋表面粉尘输入的更好代理，确定是否有任何部分是人为的，以及是否有任何Ga与有机物络合，从而产生可能的Ga-Fe竞争性相互作用。

ABSTRACTOCE-0137359Reactive trace species such as Fe have an important effect on surface ocean chemistry and biological productivity. However, other trace species that can influence primary production, affect the chemical distribution of other elements or can be used as tracers have received less attention. For this reason, two PIs from the University of Southern Mississippi will participate in the 4th IOC cruise to the Northwest Pacific to determine Mn, H2O2 and Ga in surface waters, vertical profiles, rain samples, dust dissolution experiments and/or incubation experiments. Determinations of H2O2 will be used for the following: (1) add measurements to a growing dataset aimed at examining photochemical dissolution of dust in surface waters; (2) determine whether it aids in the solubilization of particulate Fe in the surface ocean; and (3) assess rates of photo-production and dark decay. Values for Mn will be compared with Al and Ga to differentiate dust from shelf inputs. In addition, given the longer residence time for Mn in the surface ocean, the PI will attempt to use this metal to provide new insights into Fe inputs to the upper ocean. Comparison of Mn with H2O2 will allow the PIs to determine reductive dissolution of manganese oxides in seawater. Lastly, Ga concentrations will be compared with Al to assess if the former may not be a better proxy for dust inputs to the surface ocean, determine if any fraction is anthropogenic and whether any of the Ga is complexed with organics creating possible Ga-Fe competitive interactions.